<!DOCTYPE html>
<html>
	<head>
		<meta charset="utf-8">
		<title></title>
		<style type="text/css">
			.conta{
				height: 300px;
				width: 450px;
				background-color: #7FFF00;
				display: flex;
				flex-direction: row;
				justify-content: space-around;/* X轴 */
				align-content: space-between;/* Y轴 */
				align-items: center;
				flex-wrap: wrap;
			}
			.d1{
				width: 100px;
				height: 100px;
				background-color: #008000;
				color: #FFFFFF;
			}
			.btn{
				width: 300px;
				display: flex;
				justify-content: space-around;
			}
		</style>
	</head>
	<body>
		<!-- 单根节点 -->
		<div class="conta">
			<div class="d1" style="order: 2; align-self: stretch;">1</div>
			<div class="d1" style="order: 0;">2</div>
			<div class="d1" style="order: 4;">3</div>
			<div class="d1" style="order: 1;">4</div>
		</div>
		<div class="btn">
			<button style="width:50%;" type="button">登录</button>
			<button style="width:50%;" type="button">注册</button>
		</div>
	</body>
</html>
